Late on a Wednesday night last month a motorcyclist was zooming home across Washington, enjoying the cool evening air when his rear tire went Pfffft.

Luckily, he thought, a service station was near. Luckily, he thought, the station had an air hose that was connected even when the station closed. Luckily, he thought, he had a spare tube in the saddlebags and tools to make the change.

Two and half hours later, his knuckles skinned, his patience exhausted and his mind turning to putty, he thought how lucky it really would have been if he just drove a car like everyone else.

Five years ago, when the Arabs first said whoa and the world discovered what life is like without gasoline, thousands of Americans raced to the nearest motorcycle shop and plunged into life on two wheels.

One year later, when things cooled down, thousands of Americans discovered they were now proud possessors of vehicles they probably never would use again for more than recreational Sunday jaunts. Most sold out.

Now comes fuel fever, stage II, and motorcycle dealers are feeling the crunch again.

"We've had a good spring in sales and the weather has been rotten," said Bill Blalock at Blalock Cycles in Wheaton. "If it takes off again I don't think we'll be able to even keep up with demand. We expected a real downturn this year, with the dollar's decline against Japanese currency. It isn't happening."

In Virginia, spring sales are up 20 per cent over last year at Cycles/Arlington, a major distributor. Sales manager John Bingham figures that's only the tip of the iceberg, and added that moped sales are already climbing at a "phenomenal rate."

Bingham watches who's coming in, and said that about half the bike sales are to people either buying their first motorcycle or getting back into the sport after a hiatus of some years. Almost all cite fuel shortages as among their reasons.

Which raises a point.

Are motorcycles and mopeds sensible alternatives in a fuel-starved economy? Are they reasonable commuting vehicles? Can they take the place of the family car?

Even the people who sell them for a living are unwilling to give an unequivocal yes.

Bingham and his colleagues once did a little calculating and determined that to make up the estimated $1,500 price tag of an average bike in fuel savings, the driver would have to keep it 115 years.

"The motorcyle is basically a recreational thing. The fuel situation just gives people a rationale for buying one. They can say, 'Hey, honey, if I buy a bike we can save on gas.'"

After some of his experiences in 1974 Blalock has even taken to trying to dissuade some prospective buyers from going through with it.

"We had women coming in in high heels saying, 'I want a motorcycle.' We had older men in poor health. People who had no business on a motorcycle. They didn't even know the brand names. I'd say half the people who bought them sold out again in a year."

But times are changing.

"People seem to be thinking about a little more this time. They're coming in and asking sensible questions. And if they don't belong on a bike we tell them so."

Both Blalock and Bingham have formulas worked out for matching people to the bikes they need. Both agree that a bike that's too small is as dangerous as a bike that's too big.

"Everyone wants to know how fast it will go," said Blalock. "I'll show them a little 125 cc and the top end is 70. They say, 'Well, I never want to go 70 anyway,' and buy it. What they don't realize is that top end means nothing. The cruising speed a bike will maintain on the highway under any conditions is what counts. A 125 will do 70, but going uphill against the wind on the Beltway it may drop down to 35. That's when cars start crowding and there's no place to go."

The popular commuting bike for folks who use the highways these days is a 400 cc. It has adequate crusing speed and gets 50 miles or more per gallon.

For in-town-only riding, the recommendation is for a 100 cc or 125 cc bike, which may get 80 miles per gallon.

Bingham, who sells mopeds by the truck-load, thinks riders are more careful and safer on small motorcycles. "They tend to get a cavalier attitude on a moped," he said. "They figure they don't need a helmet, they don't need tags and they're only going 25 miles an hour."

Moped sales, he finds, are mostly to youngsters aged 16 to 18 and to men and women over 40 who "don't want to fire up the LTD to go buy a pack of cigarettes."

The trend in bikes, then, seems to be toward the broad middle-of-the-road. Tiny machines are making inroads, but interest in the giant 1,000-cc-and-up models which seldom get better than 35 miles to a gallon anyway, is tailing off.

As for safety, the dangers of motorcycling are well enough known that they need no recounting. Suffice it to say that the good motorcyclist needs the athletic skills of an acrobat and the mind of a psychiatrist to stay out of trouble.

"You have to be able to read a guy's mind by looking at the back of his head through a car window at 50 yards," said a veteran.

One fact bears repeating. The vast majority of serious motorcycle accidents occur within the first three months of driving. Ask any rider.

There is one more myth about motorcycles that needs dispelling - that they dispense with waiting around in gas lines.

The average bike has a three or four-gallon tank. It gets 50 or 60 miles per gallon of fuel. That means it has a range of 150 or 200 miles - less than most cars.

So while the trips to the pumps are less costly, they won't be any less frequent.

Unless you do what Bingham says some of his clients are already considering - park the car and use it as a fuel-storage bin to siphon bike gasoline from.

Times are hard, but are they that hard already? CAPTION: Picture, no caption, By James A. Parcell.